Method for setting user equipment identifier in radio communication system

ABSTRACT

The present invention is directed to a method for setting a user equipment identifier as user equipment identification information used when data received through a dedicated logical channel is transmitted through a common transport channel. The method includes transmitting data and a message type indicator as user equipment identification information from a RRC layer to an RLC layer; setting a user equipment identifier indicator according to the received message type indicator in the RLC layer and transmitting it with the data to a MAC layer; and selecting a user equipment identifier type and a user equipment identifier according to the set user equipment indication identifier, adding it to a header of a MAC SDU in the MAC layer and transmitting it to a corresponding MAC layer in a receiving device.

CROSS REFERENCE TO RELATED ART

This application is a continuation of U.S. patent application Ser. No.12/427,632, filed Apr. 21, 2009, which is a continuation of U.S. patentapplication Ser. No. 10/191,260, filed Jul. 8, 2002 (now U.S. Pat. No.7,551,643, issued Jun. 23, 2009), and claims priority to Korean PatentApplication No. 2001-40710, filed Jul. 7, 2001, each of which isincorporated by reference herein in their entireties.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method for setting a terminal (userequipment) identifier in a mobile communication system as terminal (userequipment) identification information, when data delivered through adedicated logical channel is transmitted through a common transportchannel. More specifically, it relates to a method for setting a userequipment identifier in a UMTS (Universal Mobile TelecommunicationsSystem, European type IMT-2000 radio communication system). As data (RLCSDU; Radio Link Control Service Data Unit) and message type indicator,which serve the purpose of user equipment identification information,are transmitted from a RRC (Radio Resources Control) layer to an RLC(Radio Link Control) layer, the RLC layer sets a user equipmentidentifier indicator according to the transmitted message type indicatorand transmits it with the data to a MAC (Medium Access Control) layer.In turn, the MAC layer adds the appropriate user equipmentidentification information to the data received.

2. Description of the Related Art

For the purpose of making specifications for third generation mobilecommunication systems (IMT-2000 systems) based on evolved GSM corenetwork and W-CDMA radio access network and specifications for userequipment for the system, a group of standard developing organizations(SDOs) including ETSI of Europe, ARIB/TTC of Japan, Ti of U.S. and TTAof Korea established a unified SDO in the name of Third GenerationPartnership Project (“3GPP”). 3GPP is developing third generation mobilecommunication systems (IMT-2000 system) providing high performancemultimedia services including audio, video and data over a radionetwork.

For the purpose of efficient management and technological development,five Technical Specification Groups (“TSGs”) are organized under 3GPP.Each TSG is in charge of approving, developing and managingspecifications related to a pertinent field. Among them, RAN (RadioAccess Network) group has developed functions, requirements andinterface specifications related to user equipment and UMTS (UniversalMobile Telecommunications System, European type IMT-2000 System)Terrestrial Radio Access Network (“UTRAN”) in order to set a new radioaccess network specification to the third generation mobilecommunication system.

A TSG-RAN group consists of one plenary group and four working groups.WG1 (working group 1) has been developing specifications for a physicallayer (first layer), and WG2 has been specifying functions of a datalink layer (second layer) and a network layer (third layer). Inaddition, WG3 has been developing specifications for interfaces amongbase stations, RNCs (Radio Network Controller) and core networks in theUTRAN. Lastly, WG4 has been discussing requirements for radio linkperformance and radio resource management.

FIG. 1 illustrates a structure of the UTRAN.

As depicted in FIG. 1, the UTRAN 20 includes a Node B and an RNC. Node Bis controlled by the RNC, and works as an access point by receivinguplink information from the user equipment 10 and by transmittingdownlink information from the UTRAN through the physical layer linking.The RNC performs allocation and management of radio resources.

The RNC can be classified as either control or serving RNC. First, thecontrol RNC directly manages Node B and manages common radio resources.Next, the serving RNC manages dedicated radio resources allocated toeach user equipment.

The control RNC and the serving RNC can be the same. However, when auser equipment moves from a serving RNC's region to other RNC's regions,a control RNC and a serving RNC can be different.

Accordingly, when the control RNC and the serving RNC are different,data to be transmitted to a user equipment is transmitted to a controlRNC after passing through a serving RNC and transmitted to a userequipment through a Node B connected to the control RNC.

As depicted in FIG. 1, a Radio Network Sub-system (“RNS”) includes oneRNC and several Node Bs. In addition, the RNS where a serving RNC islocated is referred to as serving RNS.

FIG. 2 illustrates a structure of a general radio interface protocolaccording to a radio access network specification of the 3GPP.

A radio interface protocol between a user equipment and the UTRAN ishorizontally divided into a physical layer (first layer), a data linklayer (second layer) and a network layer (third layer). It is alsovertically divided into a control plane for control signaling and a userplane for data information transfer.

As to the vertical division, first, the control plane contains a radioresource control (“RRC”) layer, a radio link control (“RLC”) layer, amedium access control (“MAC”) layer and a physical layer as the firstlayer. Next, the user plane contains a packet data convergence protocol(“PDCP”) layer, a broadcast/multicast control (“BMC”) layer, an RLClayer, a MAC layer and a physical layer.

The physical layer provides information transfer service to an upperlayer by using various radio transfer techniques. It is connected to theMAC layer as an upper layer through transport channels. The data betweenthe MAC layer and the physical layer are transmitted through thetransport channels. The transport channels are classified as a DTCH(Dedicated Transport Channel) and a CTCH (Common Transport Channel). TheDTCH is a transport channel exclusively used by one user equipment, andthe CTCH is a transport channel jointly used by several user equipment.

The MAC layer provides a reallocation service of a MAC parameter forallocating and reallocating radio resources. It is connected to the RLClayer through a logical channel, and various logical channels areprovided according to the type of information transmitted. In general, acontrol channel is used when transmitting information on the controlplane, and a traffic channel is used when transmitting information onthe user plane.

The RLC layer provides the function of setting and releasing radiolinks. In addition, it performs segmenting and reassembling functions ofan RLC Service Data Unit (“SDU”) delivered from an upper layer on theuser plane. The size of the RLC SDU is adjusted on the RLC layer to besuitable for a processing capacity. Afterwards, header information isadded, and it is transmitted to the MAC layer as an RLC Protocol DataUnit (“PDU”) format.

Since the PDCP layer is an upper layer of the RLC layer, it converts thedata of packet network protocols, such as IPv4 or IPv6, into the data ofa format suitable for the RLC layer, and vice versa. In addition, itassists the lower layers to transfer data through the radio interfaceefficiently by reducing unnecessary control information used in a wirenetwork. That function is referred to as header compression, and, forexample, the header compression can be used to reduce TCP/IP headerinformation.

The BMC layer exists on the user plane, and it is used for applying abroadcast service or a multicast service to the system having a radiointerface.

The RRC provides information broadcast services to all user equipmentlocated within a certain area. In addition, it performs a control planesignal processing for a control signal exchanging between the thirdlayers of transmitting and receiving side and has functions forsetting/maintaining/releasing radio resources between user equipment andthe UTRAN. In particular, the RRC has functions forsetting/maintaining/releasing a Radio Bearer andallocating/reconfiguring/releasing radio resources required for radioaccess networking. Herein, the Radio Bearer means a service provided bythe second layer for data transfer between the user equipment and theUTRAN. That is, setting a radio bearer means specifying thecharacteristics of a protocol layer and a channel required to provide acertain services, and setting specific parameters and operation method.

Each user equipment also includes all radio interface layers. However,in the UTRAN, protocol layers are dispersed in several constituentelements of a UTRAN (UMTS Terrestrial Radio Access Network).

FIG. 3 illustrates an example of a protocol layer hierarchycorresponding to the constituent elements of a Radio Access Network. Ingeneral, the RLC layer is placed in the serving RNC. The functions ofthe MAC layer can be divided according to the type of a transportchannel and can be placed either in the serving RNC or in the controlRNC.

As depicted in FIG. 3, when two RNCs are operated concurrently as aserving RNC and a control RNC, the MAC layer is divided into a MAC-d sublayer and a MAC-c/sh sub layer according to the type of transportchannel. These are respectively placed in the serving RNC and thecontrol RNC.

In comparison, when one RNC is operated commonly as the serving RNC andthe A) control RNC, a MAC-c/sh sub layer and a MAC-d sub layer areplaced on the same RNC. This is because the MAC-d sub layer manages adedicated logical channel, which is dedicated to a user equipment, andthe MAC-c/sh sub layer manages a common transport channel. Because theMAC-s/sh sub layer manages the common transport channel, which isjointly used by all user equipment within the cell, each cell has oneMAC-c/sh layer. Because the MAC-d sub layer provides a dedicated serviceto a user equipment, and one MAC-d sub layer exists for each one userequipment. The physical layer (PHY) is placed in the Node B.

FIG. 4 illustrates a structure of an RLC layer and a MAC layer in theUTRAN. In a down_link, when data is delivered to the RLC layer from anupper layer, the RLC layer stores an RLC PDU in an RLC buffer andtransmits a certain number of PDUs corresponding to a request from theMAC layer.

The RLC PDU received in the MAC-d layer is transmitted through DedicatedTransport Channel (DTCH) or Common Transport Channel (CTCH) by channelswitching. When it is transmitted through DTCH, a related header isadded to it in the MAC-d sub layer, and it is transmitted to thephysical layer through a Dedicated Channel (DCH).

However, the RLC PDU is transmitted through the CTCH, it is transmittedfrom the MAC-d sub layer to the MAC-c/sh sub layer, and a related headeris added on. Thereafter, it is multiplexed through other logicalchannels and is transmitted through the common transport channel such asPCH (Paging Channel), FACH (Forward Access Channel) and DSCH (DownlinkShared Channel) etc.

In an up_link, data is received through the Dedicated Channel (DCH) andthe common transport channel (CTCH) such as RACH (Reverse AccessChannel) and CPCH (Common Packet Channel) etc., and the data issubsequently transmitted to an upper layer.

In that case, the data is transmitted to the RLC layer via the pathconverse in the down_link. The structures of the RLC layer and the MAClayer in the user equipment are almost the same as the structure in FIG.4.

To illustrate, the transmission of data through FACH (Forward AccessChannel) as the common transport channel will be described withreference to FIG. 4.

Because the RLC PDU transmitted from the RLC layer uses the FACH of theMAC-c/sh sub layer, it is transmitted to the MAC-c/sh sub layer throughchannel switching and control transmission multiplexing. The controltransmission multiplexing means multiplexing several logical channels.

Data transmitted to the MAC-c/sh sub layer is multiplexed with data ofother logical channels. In addition, because the data of various userequipment can be transmitted through the common transport channel, toidentify a user equipment to receive pertinent data, a destination userequipment's identifier is added to the MAC PDU through a user equipmentidentifier inserting for data multiplexing. Herein, a TCTF (TargetChannel Type Field) mapping for data multiplexing maps the relationshipbetween the logical channel and the transport channel. Data mapped bythe FACH transport channel is transmitted to the FACH based on a datatransmission schedule by considering the priority of the user equipment.

The RLC PDU delivered from the RLC layer of the UTRAN or the userequipment to the MAC layer through the logical channel is transmitted tothe physical layer through an appropriate transport channel.

Herein, when the data passed the dedicated logical channel istransmitted through the common transport channel as described above, itpasses through the MAC-d sub layer and the Mac-c/sh sub layer andultimately transmitted to the physical layer.

In that case, MAC PDU header information, which is added by each part ofthe MAC layer, can include a TCTF field, a user equipment identifiertype field, a user equipment identifier field and a C/T field etc.

The TCTF field indicates the following: the type of a logical channelthe data of which is transmitted through a specific transport channel;the user equipment identifier type field indicating which user equipmentidentifier among various types of user equipment identifiers is used;the user equipment identifier field including identification informationof a user equipment designated in the user equipment identifier typefield; and the CIT field which provides information for distinguishingeach logical channel when data of several logical channels aretransmitted to one transport channel.

A user equipment identifier, used for identifying a user equipment onthe MAC-c/sh sub layer shown in FIG. 4, can be divided into two typesaccording to a user equipment's distinguishable geographical region(i.e. a range in which each user equipment can cover) in a network.

First, a C-RNTI (Cell Radio Network Temporary Identity) is allocated bythe control RNC when a user equipment is linked to a new cell.Accordingly, the C-RNTI has unique value only in a pertinent cell, and acell region is the effective region of the C-RNTI. Therefore, when theuser equipment moves to another cell, the C-RNTI has to be changed.

Second, a U-RNTI (UTRAN Radio Network Temporary Identify) is used foridentifying a certain user equipment in the UTRAN, and it is composed ofa S-RNTI (SRNC RNTI) and a serving RNC identifier. The S-RNTI is anidentification value used for identifying a certain user equipment inthe serving RNC, and each user equipment has a unique S-RNTI value inthe serving RNC. In addition, the serving RNC identifier is used toidentify the RNC in the UTRAN. Accordingly, in order to designate acertain user equipment in the UTRAN, serving RNC identifier informationand an identification value of the user equipment in the pertinent RNCare required.

Accordingly, the U-RNTI is a unique value in the UTRAN and is notchanged even in cases where the use equipment is moved to a differentcell in a RNS. However, when the serving RNC identifier is changed dueto the change of the serving RNC, a new U-RNTI value has to beallocated. More specifically, a U-RNTI effective range is a regionmanaged by a serving RNC.

In a system compliant with the 3GPP standard, a user equipment isidentified by using only one of the two types of user equipmentidentifier: with the C-RNTI, a 16 bit is required, and with the U-RNTI,a 32 bit is required. Accordingly, by using C-RNTI the limited radiochannel resources can be efficiently used. In some cases, a value of theU-RNTI is used. For example, when a C-RNTI value is changed frequently,a user equipment can be identified effectively by using a U-RNTI value.

However, in the conventional system compliant with the 3GPP standard,identification information of a user equipment is added to a MAC PDU bythe MAC layer of the transmitter side, and the identificationinformation of the user equipment is identified in the receiver side ofthe MAC layer. Though, the transmitter side MAC layer performsmultiplexing of an RLC PDU transmitted from the RLC layer and addingidentification information of a user equipment to a MAC PDU (a data unitcorresponding to the RLC PDU), the MAC layer is unable to recognize whenand which type of user equipment identifier is used, and can not changethe type of user equipment identifier dynamically.

SUMMARY OF THE INVENTION

In order to facilitate in determining when and which type of a userequipment identifier must be used in a MAC layer, a method fordetermining information required for setting a user equipment identifier(C-RNT, U-RNTI) from other layers to a MAC (Medium Access Control) layerand a method for setting a user equipment identifier value are explainedbelow.

Additional features and advantages of the invention will be set forth inthe description which follows, and in part will be apparent from thedescription, or may be learned by practice of the invention. Theobjectives and other advantages of the invention will be realized andattained by the structure particularly pointed out in the writtendescription and claims hereof as well as the appended drawings.

To further illustrate, when data received through a dedicated logicalchannel is transmitted through a common transport channel, it isnecessary to distinguish a user equipment which is the destination ofthe data by using a user equipment identifier in the MAC layer. Thus, amethod for setting a user equipment identifier, which is to be added toa MAC PDU header, is provided below.

The steps in setting a user equipment identifier with the presentinvention are as follows: 1) transmitting data and a message typeindicator as user equipment identification information from a RRC (RadioResources Control) layer to an RLC (Radio Link Control) layer; 2)setting a user equipment identifier indicator according to the receivedmessage type indicator in the RLC layer and transmitting it with thedata to a MAC (Medium Access Control) layer; 3) selecting a userequipment identifier type and a user equipment identifier according tothe set user equipment indication identifier, adding it to a header of aMAC PDU (Medium Access Control Protocol Data Unit) in the MAC layer; and4) transmitting it to a reception side MAC layer. (A MAC PDU is composedof a header and a MAC SDU. MAC SDU is substantially the same as RLCPDU.) The method further includes: performing a radio transmission inthe MAC layer as a MAC PDU (Medium Access Control Protocol Data Unit)format; adding a user equipment identifier type field indicating a userequipment identifier field and the type of a user equipment identifierto the MAC PDU header; and transmitting it to the reception side anddistinguishing a user equipment by using the MAC PDU header informationin the reception side.

The RLC layer receives data (RLC SDU) and a message type indicator asuser equipment identification information from the RRC layer and sets auser equipment identifier indicator for distinguishing a user equipmentappropriate to a network region managing the user equipment in a mobilecommunication system. The MAC layer receives the user equipmentidentifier indicator designating the type (U-RNTI, C-RNTI) of userequipment identifier, and the MAC layer sets user equipment identifierand a user equipment identifier type field as MAC PDU headerinformation.

The type of a user equipment identifier is determined when setting theradio bearer, and the set user equipment identifier indicator istransmitted from the RLC layer to the MAC layer in a transmissionsession using the set radio bearer.

The user equipment identifier indicator is updated by controlinformation on the RRC layer when the type of user equipment identifieris changed.

The type of user equipment identifier is set according to the type ofdata (RLC SDU) transmitted from the RRC layer to the RLC layer.

According to an embodiment of the present invention, a method forsetting a user equipment identifier in a radio communication systemhaving a plurality of protocol layers comprises: providing data and aparameter associated with a user equipment identifier type indicatorfrom a third protocol layer to a second protocol layer, wherein thethird protocol layer is an upper protocol layer than the second protocollayer; providing the user equipment identifier indicator and the datafrom the second protocol layer to a first protocol layer; and adding inthe first protocol layer a user equipment identifier type and a userequipment identifier to a first protocol layer data packet in responseto the user equipment identifier indicator.

According to one aspect of the present invention, the third protocollayer is preferably a radio resource control (RRC) layer, the secondprotocol layer is preferably a radio link control (RLC) layer, and thefirst protocol layer is preferably a medium access control (MAC) layer.

According to another aspect of the present invention, the first protocollayer data packet is an MAC service data unit (SDU). In addition, a MACprotocol data unit (PDU) comprises the MAC SDU and the user equipmentidentifier.

According to another aspect of the present invention, the user equipmentidentifier indicator is associated with at least one of cell radionetwork temporary identity (C-RNTI) and UTRAN radio network temporaryidentity (U-RNTI). The MAC layer receives the MAC SDU and the userequipment identifier indicator indicating a user equipment typeassociated with a radio network temporary identity (RNTI), and settingthe user equipment identifier type and the user equipment identifier aspart of MAC PDU.

According to another aspect of the present invention, the user equipmenttype is used in determining radio resource settings of a radio bearer,and the user equipment identifier indicator is transmitted from thesecond protocol layer to the first protocol layer. Preferably, the userequipment identifier indicator is dynamically updated by controlinformation of the third protocol layer when the user equipment typeused in a radio communication network has changed.

According to another embodiment of the present invention, a radiocommunication system for identifying user equipment in a radiocommunication network comprises a plurality of protocol layers; meansfor providing data and a message type indicator from a RRC (radioresources control) layer to an RLC (radio link control) layer, whereinthe message type indicator is associated with a user equipmentidentifier indicator; means for setting in the RLC layer the userequipment identifier indicator in response to the received message typeindicator; means for providing the user equipment identifier indicatorand the data to a MAC (medium access control) layer; and means foradding in the MAC layer a user equipment identifier type and a userequipment identifier to a header of a MAC SDU (medium access controlservice data unit) in response to the user equipment identifierindicator.

According to another embodiment of the present invention a radiocommunication system for identifying user equipment in a radiocommunication network comprises a plurality of protocol layers; meansfor providing data and a parameter associated with a user equipmentidentifier type indicator from a third protocol layer to a secondprotocol layer, wherein the third protocol layer is an upper protocollayer than the second protocol layer; providing the user equipmentidentifier indicator and the data from the second protocol layer to afirst protocol layer; and adding in the first protocol layer a userequipment identifier type and a user equipment identifier to a firstprotocol layer data packet in response to the user equipment identifierindicator.

The foregoing and other objects, features, aspects and advantages of thepresent invention will become more apparent from the following detaileddescription of the present invention when taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention.

In the drawings:

FIG. 1 illustrates a UTRAN (Universal Mobile Telecommunications NetworkTerrestrial Radio Access Network) structure according to a 3GPP (ThirdGeneration Partnership Project) radio access network specification asapplied to the conventional art and the present invention;

FIG. 2 illustrates a structure of a general radio interface protocolaccording to a radio access network specification provided by the 3GPP;

FIG. 3 illustrates an example of a protocol layer structured by radioaccess network construction elements;

FIG. 4 illustrates a structure of an RLC (Radio Link Control) layer anda MAC (Medium Access Control) layer in the UTRAN side;

FIG. 5 illustrates a MAC PDU (Medium Access Control Protocol Data Unit);

FIG. 6 is a flow chart illustrating a static setting of a user equipmentidentifier indicator in accordance with the present invention; and

FIG. 7 is a flow chart illustrating a dynamic setting of a userequipment identifier indicator in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. Hereinafter, a method for setting a user equipment identifierin accordance with the present invention will be described.

Initially, the use of each user equipment identifier (for example,C-RNTI, U-RNTI) will be described. First, in a radio communicationnetwork, a C-RNTI (Cell Radio Network Temporary Identity) is used whenthe data of a DTCH (Dedicated Traffic Channel) or a DCCH (DedicatedControl Channel) as a dedicated logical channel is transmitted to acommon transport channel and when a DSCH (Downlink Shared Channel) isused as a common transport channel.

Second, a U-RNTI (UTRAN Radio Network Temporary Identity) is used whenthe data of a DCCH (Dedicated Control Channel) is transmitted to thecommon transport channel.

Accordingly, a user equipment identifier can be changed according to thetype of the logical channel used. The user equipment identifier ispreferably set in a MAC (Medium Access Control) layer. However, sincethe MAC layer cannot recognize what type of identifier is being used, ithas to receive an identifier value from an RLC layer, wherein the RLClayer is an upper layer. To further illustrate, the RLC layer has totransmit a parameter indicating the type of a user equipment identifier(for example, “0” indicating the C-RNTI or “1” indicating the U-RNTI)with an RLC PDU (Radio Link Control Protocol Data Unit).

As depicted in FIG. 5, when the parameter is referred to as a userequipment identifier indicator, a user equipment identifier type fieldin the MAC layer and a pertinent user equipment identifier indicated bya user equipment identifier indicator are added to a header of the MACPDU which includes the RLC PDU transmitted from the RLC layer.

However, because the RLC layer entity cannot recognize the type of userequipment identifier being used, a user equipment identifier ispreferably set by using the following two methods.

1. Static Setting Method—Determining the Type of a User EquipmentIdentifier in Setting a Radio Bearer.

In general, when a radio bearer is set, one or two logical channel isused in a certain RLC layer entity. That is, in most cases, one DCH(either DCCH or DTCH) is used for one RLC layer entity. In other cases,one DCCH can be added to transmit control information required for aDTCH transfer.

Accordingly, because a logical channel type is determined by setting aradio bearer, the type (U-RNTI or C-RNTI) of a user equipment identifieris also determined when setting a radio bearer. Once set, the userequipment identifier type is continually used until the setting of theradio bearer is changed.

In other words, an RLC layer indicates the same user equipmentidentifier to the MAC layer. When a need to change the type of the userequipment identifier arises, the setting of the radio bearer is changed,and accordingly a different type of user equipment identifier may beused.

2. Dynamic Setting Method—Determining the Type of a User EquipmentIdentifier According to the Type of Transmitted Message.

The static setting method described above may be simple to implement.However, the same type of a user equipment identifier is used with acertain radio bearer. For example, when a radio bearer is set to useU-RNTI (required 32 bits) for a case permitting using C-RNTI (required16 bits), resource waste might arise in comparison with the use ofC-RNTI.

Accordingly, with the preferred embodiment of the present invention, amethod for distinguishing a case using U-RNTI information and a caseusing C-RNTI information and indicating the type of a user equipmentidentifier to be used in a MAC layer in transmission of pertinentinformation and for informing it to an RLC layer will be used.

As described above, since only C-RNTI is used when DTCH is used as alogical channel, the dynamic user equipment identification methodaccording to the preferred embodiment of the present invention will bedescribed in connection with the DCCH.

In general, the DCCH is a logical channel for transmitting controlinformation transmitted from a RRC (radio resources control) layer. AnRRC message includes information related to call setting, maintainingand releasing functions.

The RRC layer performs a function for supporting a call connection toprevent disconnecting during a user equipment transfer from one cell (ornode) to another cell (or another node). In some cases, a C-RNTI valuemay vary. In that case, it is proper to use a U-RNTI as user equipmentidentifier information. However, in most cases, it is possible toidentify a user equipment with a C-RNTI, and accordingly resource wastecan be minimized by selectively choosing a particular type of a userequipment identifier.

In addition, only the RRC layer recognizes what user equipmentidentifier type (C-RNIT or U-RNTI) is required when during thetransmission of a RRC message, and the RRC layer has to transmit arelated parameter to the RLC layer.

The parameter is preferably called “message type indicator”. Forexample, in the RRC layer, a message to be transmitted requires aU-RNTI. First, the RRC layer transmits an RLC SDU with a message typeindicator indicating a U-RNTI. Then the RLC layer sets a user equipmentidentifier according to the message and transmits the set indicator withan RLC PDU to the MAC layer.

Alternatively, assuming a message to be transmitted in the RRC layerrequires a C-RNTI, the RRC layer transmits an RLC SDU having a messagetype indicator indicting a C-RNTI. The RLC layer sets a user equipmentidentifier according to the message and transmits the set indicator witha MAC SDU (substantially the same as RLC PDU) to the MAC layer.

FIG. 7 is a flow chart illustrating a static setting of the type of auser equipment identifier based on an embodiment of the presentinvention.

In setting a radio bearer, the RLC layer sets a user equipmentidentifier to be used, then transmits the set indicator to the MAC layerwith a MAC SDU, and accordingly a user equipment identifier type fieldand a user equipment identifier field are set as shown in steps 71˜73.

When the need arises, the user equipment identifier type is altered bychanging the radio bearer setting as shown in steps 73 and 71.

FIG. 6 is a flow chart illustrating a dynamic setting of the type of auser equipment identifier based on the preferred embodiment of thepresent invention.

It describes a dynamic determining method of the type of user equipmentidentifier in a Radio Access Network.

The RLC layer receives an RLC SDU and a message type indicator from theRRC layer as shown in step 61.

Afterwards, the RLC layer checks the message type indicator, judgeswhich one (between a U-RNTI and a C-RNTI) is to be used in thetransmission of a pertinent MAC SDU, sets a user equipment identifierindicator and transmits it to the MAC layer with the MAC SDU as shown insteps 62˜65.

In the meantime, in steps 62˜64, the RLC layer segments and reassemblesthe RLC SDU. The messages (usually not less than two) can eitherconstruct one RLD PDU, or several RLC PDUs can construct one message. Inparticular, when a plurality of messages form one RLC PDU, the type ofuser equipment identifier indicator used for each message can bedifferent (for example, a first message may be associated with U-RNTIand a second message may be associated with C-RNTI). In that case, auser equipment identifier indicator is set to construct a header of aMAC PDU by using only a U-RNTI (32 bit) as a broader conceptualidentifier.

In addition, when data of at least two types of RLC SDUs are included inone RLC PDU and the same type of user equipment identifier indicator isused for the SDUs, the same user equipment identifier indicator istransmitted to the MAC layer with the MAC SDU (substantially same as theRLC PDU).

Preferably, a message type indicator and a user equipment identifierindicator refers to the same thing. However, because segmenting andreassembling of an RLC SDU are performed on the RLC layer, a userequipment identifier indicator of the RLC PDU is set based on themessage type indicator.

As described above, in the preferred embodiment of the presentinvention, data (RLC SDU) and a message type indicator as user equipmentidentification information are transmitted from the RRC layer to the RLClayer. Then the RLC layer sets a user equipment identifier indicatoraccording to the transmitted message type indicator and transmits it tothe MAC layer with the data, and appropriate user equipmentidentification information is added in the MAC layer.

Furthermore, when data transmitted or received through a dedicatedlogical channel is transmitted through a common transport channel and itis required to distinguish a user equipment by using a user equipmentidentifier, radio resource waste can be minimized by not setting onekind of user equipment identifier in a lump but setting an appropriateuser equipment identifier as occasion demands.

The preferred embodiments may be implemented as a method, apparatus orarticle of manufacture using standard programming and/or engineeringtechniques to produce software, firmware, hardware, or any combinationthereof. The term “article of manufacture” as used herein refers to codeor logic implemented in hardware logic (e.g., an integrated circuitchip, Field Programmable Gate Array (FPGA), Application SpecificIntegrated Circuit (ASIC), etc.) or a computer readable medium (e.g.,magnetic storage medium (e.g., hard disk drives, floppy disks, tape,etc.), optical storage (CO-ROMs, optical disks, etc.), volatile andnon-volatile memory devices (e.g., EEPROMs, ROMs, PROMs, RAMs, DRAMs,SRAMs, firmware, programmable logic, etc.). Code in the computerreadable medium is accessed and executed by a processor. The code inwhich preferred embodiments are implemented may further be accessiblethrough a transmission media or from a file server over a network. Insuch cases, the article of manufacture in which the code is implementedmay comprise a transmission media, such as a network transmission line,wireless transmission media, signals propagating through space, radiowaves, infrared signals, etc. Of course, those skilled in the art willrecognize that many modifications may be made to this configurationwithout departing from the scope of the present invention, and that thearticle of manufacture may comprise any information bearing medium knownin the art.

As the present invention may be manifested in several forms withoutdeparting from the spirit or essential characteristics thereof, itshould also be understood that the above-described embodiments are notlimited by any of the details of the foregoing description, unlessotherwise specified. On the other hand, it should be construed broadlywithin its spirit and scope as defined in the appended claims, andtherefore all changes and modifications that fall within the metes andbounds of the claims, or equivalence of such metes and bounds aretherefore intended to be embraced by the appended claims.

As the present invention may be manifested in several forms withoutdeparting from the spirit or essential characteristics thereof, itshould also be understood that the above-described embodiments are notlimited by any of the details of the foregoing description, unlessotherwise specified. On the other hand, it should be construed broadlywithin its spirit and scope as defined in the appended claims, andtherefore all changes and modifications that fall within the metes andbounds of the claims, or equivalence of such metes and bounds aretherefore intended to be embraced by the appended claims.

1. A method of transmitting a dedicated data on a common transportchannel in a mobile communication system having a plurality of protocollayers, the method comprising: transmitting the dedicated data and arelated parameter indicating one among two or more user equipmentidentifier types from a fourth protocol layer to a third protocol layer;transmitting the dedicated data and the related parameter from the thirdprotocol layer to a second protocol layer through one or more dedicatedlogical channels; performing transport channel type switching to acommon transport channel; multiplexing a target channel type field(TCTF), the related parameter, a user equipment identifier and thededicated data in order to construct a protocol data unit, wherein theuser equipment identifier is determined based on the related parameter;and transmitting the protocol data unit through the common transportchannel from the second protocol layer to a first protocol layer.
 2. Themethod of claim 1, furthering comprising: recognizing what userequipment identifier type is required when transmitting the dedicateddata on a common transport channel, and determining the relatedparameter in the fourth layer.
 3. The method of claim 1, wherein thesecond layer comprises a first entity and second entity, the step forperforming transport channel type switching is performed by the firstentity and the step for multiplexing is performed by the second entity.4. The method of claim 3, wherein the first entity is a MAC-d entity andthe second entity is a MAC-c/sh entity.
 5. The method of claim 3,wherein the first entity multiplexes a field for distinguishing eachlogical channel when data of a plurality of logical channel aretransmitted to the common transport channel.
 6. The method of claim 1,wherein the related parameter is changed according to the type of thededicated logical channel used.
 7. The method of claim 1, wherein therelated parameter indicates a type associated with a radio networktemporary identifier (RNTI).
 8. The method of claim 1, wherein thededicated logical channel is DTCH or DCCH.
 9. The method of claim 1,wherein the common transport channel is FACH or RACH.
 10. The method ofclaim 1, wherein the related parameter is dynamically updated by controlinformation of the upper protocol layer when the related parameter usedin a radio communication network has changed.
 11. An apparatus fortransmitting a dedicated data on a common transport channel in a mobilecommunication system, the apparatus comprising: a first entity fortransmitting the dedicated data and a related parameter indicating oneamong two or more user equipment identifier types from a fourth protocollayer to a third protocol layer; a second entity for transmitting thededicated data and the related parameter from the third protocol layerto a second protocol layer through one or more dedicated logicalchannels; a third entity for performing transport channel type switchingto a common transport channel; and a fourth entity for multiplexing atarget channel type field (TCTF), the related parameter, a userequipment identifier and the dedicated data in order to construct aprotocol data unit, and transmitting the protocol data unit through thecommon transport channel from the second protocol layer to a firstprotocol layer, wherein the user equipment identifier is determinedbased on the related parameter.
 12. The apparatus of claim 1, whereinthe first entity recognizes what user equipment identifier type isrequired when transmitting the dedicated data on a common transportchannel, and determines the related parameter.
 13. The apparatus ofclaim 1, wherein the third entity and the fourth entity are included inthe second layer, and the second layer is a medium access layer.
 14. Theapparatus of claim 1, wherein the third entity is a MAC-d entity and thefourth entity is a MAC-c/sh entity.
 15. The apparatus of claim 1,wherein the third entity multiplexes a field for distinguishing eachlogical channel when data of a plurality of logical channel aretransmitted to the common transport channel.
 16. The apparatus of claim1, wherein the related parameter is changed according to the type of thededicated logical channel used.
 17. The apparatus of claim 1, whereinthe related parameter indicates a type associated with a radio networktemporary identifier (RNTI).
 18. The apparatus of claim 1, wherein thededicated logical channel is DTCH or DCCH.
 19. The apparatus of claim 1,wherein the common transport channel is FACH or RACH.
 20. The apparatusof claim 1, wherein the user equipment identifier type indicator isdynamically updated by control information of the upper protocol layerwhen the user equipment identifier type indicator used in a radiocommunication network has changed.